Device and method for adjusting the hook height and feeding of curtain hooks

ABSTRACT

The invention relates to a device for feeding curtain hooks, which each consists of a strip and a hook part connected thereto, to a sewing machine which can sew the strip of a supplied curtain hook to a curtain, comprising: a supply holder for the curtain hooks, displacing means for displacing one curtain hook at a time in a straight line to a desired position for sewing on the strip, and adjusting means for automatically adjusting the mutual position of strip and hook part connected thereto. The invention also relates to a method for feeding curtain hooks.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a device for feeding curtain hooks, which eachconsist of a strip and a hook part connected thereto, to a sewingmachine which can sew the strip of a supplied curtain hook to a curtain,comprising: a supply holder for the curtain hooks, displacing means fordisplacing one curtain hook at a time in a straight line to a desiredposition for sewing on the strip, and adjusting means for automaticallyadjusting the mutual position of strip and hook part connected thereto.The invention also relates to a method for feeding curtain hooks, whicheach consist of a strip and a hook part connected thereto, to a sewingmachine which can sew the strip of a supplied curtain hook to a curtain.

2. Description of the Prior Art

The automatic feed of curtain hooks to a sewing machine along a straightpath of movement is known from among others EP 0 637 345. Adjustment ofthe hook height, i.e. the mutual adjustment of a curtain hook consistingof a strip and a hook part, during the infeed route is also known fromthis publication. The use of the described device is particularlyadvantageous because it results in a reduced work load during the sewingof curtain hooks into curtains. Drawbacks of the prior art are that theexisting devices take up a relatively large amount of space and thatthey function less precisely, particularly the hook height adjustmentnot being fully controllable.

The object of the present invention is to provide an improved device andmethod for automatic height-adjustment and feed of curtain hooks,whereby the drawbacks of the prior art are obviated while the existingadvantages are retained.

SUMMARY OF THE INVENTION

The invention provides for this purpose a device of the type stated inthe preamble characterized in that the adjusting means transport acurtain hook in a circle segment-shaped path from a position close tothe underside of the supply holder to the straight line in which thedisplacing means displace a curtain hook, and during the progressionthrough this circle segment-shaped transport path the desired mutualposition of hook part and strip is adjusted. The displacement of thecurtain hooks by means of a circle segment-shaped path prior todisplacement thereof in a straight line to the sewing machine has anumber of advantages. There thus results a greater freedom of choice inrespect of the placing of the supply holder for curtain hooks; this nolonger has to be localized above the linear feed path to the sewingmachine. Particularly in the usually full curtain workshops in which thecurtains to be manufactured require much space, this results in aconsiderable improvement in the utilization of the available space. Thelinear feed to the sewing machine can also take a more compact form.These feed means, heretofore often protruding in inconvenient manner,can be given a more compact embodiment.

Another advantage of the device according to the invention is that thefirst part of the infeed route (circle segment-shaped path), includingthe hook height adjustment, is hereby separated from the second part ofthe infeed route (linear path). This implies that, while the displacingmeans for displacing curtain hooks along a straight line are inoperation, a subsequent curtain hook can already pass through the circlesegment-shaped transport path, wherein it is simultaneouslyheight-adjusted. The first part of the transport, including the hookheight adjustment, hereby need not form part of the critical path in thefeed and adjustment of curtain hooks. The device according to theinvention can hereby operate more rapidly so that productivity canincrease. A further advantage of adjusting the hook height outside thelinear transport path to the sewing machine is that this enables a morecertain locking of the strip of the curtain hook, whereby the adjustmentof the position of the hook part on the strip can also be more readilycontrolled.

In a preferred embodiment the supply holder consists of a vertical tubein which the curtain hooks are buffered stacked on top of one another.Such a buffering of hooks is already known and can also be applied incombination with the device according to the invention. This enables theinterchange of already existing supply holders with the device accordingto the invention. The advantage of the invention is that the relativelybulky supply holders can be placed at a position which is optimal for aseamstress, so that a holder is not inconvenient during use of thedevice and filling or exchanging of a supply holder is also simple.

In another preferred embodiment of the device the circle segment-shapedpath of the adjusting means ends in or close to the straight line inwhich the displacing means displace a curtain hook. The circlesegment-shaped path and the linear transport paths thus connect ontoeach other and no additional transfer means are required.

In yet another preferred embodiment the adjusting means comprise: atleast one rotatable disc, which disc is adapted to carry a curtain hook,and a stop co-acting with the disc for engaging on the hook part of thecurtain hook during rotation of the rotatable disc. Such a disc can beprovided with locking means for fixing the position of the strip of acurtain hook carried by the disc. In order to obtain the desired hookheight adjustment, an extreme working position of the stop can beadjustable, for instance by means of an adjusting member adjustable in aplurality of positions. Such adjusting means are relatively simple tomanufacture and reliable in use. When a transmission is arranged betweenthe adjusting member and the stop with a transmission ratio from adisplacement of the adjusting member to a displacement of the stop foradjusting the extreme working position which is less than 1, it is thenpossible to adjust the device with an increased accuracy. Dimensionaltolerances occurring during manufacture of the device or as a result ofwear can thus be reduced (for instance by means of regular repeated fineadjustment of the device). The transmission ratio enables a precisecontrol of the stop, with the resulting consequence that the hook heightadjustment can be extra-accurate.

The adjusting means individually as described above also form part ofthe device according to the invention.

The invention moreover provides a method of the type stated in thepreamble, comprising the successive steps of: A feeding a curtain hookfrom a supply holder along a circle segment-shaped path, a desiredmutual position of the strip and the hook part being adjusted during theprogression through this circle segment-shaped path, and B furtherdisplacing the curtain hook with adjusted hook height to a sewingmachine along a linear path connecting onto the circle segment-shapedpath. In a preferred application of this method the desired mutualposition of the strip and the hook part is determined prior toprogressing through step A by adjusting the means for feeding curtainhooks along the circle segment-shaped path. The orientation of thecurtain hook after progressing through step A is preferably also thesame as the orientation in which the curtain hook is further displacedaccording to step B. The advantages of this method are already describedabove with reference to the device according to the invention and thepreferred embodiments thereof.

BRIEF DESCRIPTION OF THE DRAWING

The present invention will be further elucidated with reference to thenon-limitative embodiments shown in the following figures. Herein:

FIG. 1 shows a top view of a curtain hook with adjustable hook height,

FIG. 2 is a perspective view of a part of a curtain with sewn-in curtainhooks,

FIG. 3 is a perspective view of a schematic representation of the deviceaccording to the invention in combination with a sewing machine, and

FIG. 4 shows a top view of a variant of the adjusting means which formpart of the device shown in FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a curtain hook 1, generally manufactured from plastic,which comprises a strip 2 with a toothing 3 and a hook part 4. Hook part4 engages on toothing 3 of strip 2 at an adjustable position. In strip 2are arranged two recesses 5 for positioning of strip 2.

FIG. 2 shows two curtain hooks 1 sewn into pleats 6 of a curtain 7. Forsimplified sewing-in thereof, the curtain hooks 1 are fed automaticallyto a sewing machine wherein the desired hook height is simultaneouslyadjusted by sliding hook part 4 relative to strip 2 until a desiredmutual position is reached.

FIG. 3 shows a schematic view of a device 8 according to the inventionin combination with a sewing machine 9. Curtain hooks 1, not shown inthis figure, are buffered in a vertical supply holder 10, which supplyholder 10 connects on the underside onto a rotatable disc 11 which formspart of adjusting means 12. Rotatable disc 11 is rotatable with anelectric motor 13 situated on the underside of rotatable disc 11.Situated between electric motor 13 and the rotatable disc 11 is a seconddisc 14 which is rigidly connected to a stop 15 which protrudes througha slot 16 in rotatable disc 11. Stop 15 engages on the hook part 4 of acurtain hook 17 lying on rotatable disc 11. An extreme position (orhook-placement position) of the second disc 14, and thus also of stop15, is determined by means of an adjusting member 18.

A curtain hook 17 fed from supply holder 10 is displaced to the shownposition in a circle segment-shaped path 19, which is shown by means ofa broken line, by rotating the rotatable disc 11. During the progressionof rotatable disc 11 through circle segment-shaped path 19 the seconddisc 14 also co-rotates, at least until it is stopped by adjustingmember 18. During displacement of curtain hook 17 the stop 15 engages onhook part 4 so that this hook part 4 is displaced relative to strip 2 ofcurtain hook 17. The end position of hook part 4 relative to strip 1 isdetermined by the extreme position of the stop 15, which correspondswith the position of the adjusting member 18 which limits the freedom ofmovement of second disc 14.

After the progression through the circle segment-shaped path 19, a rod20, which is for instance provided with fingers (not shown), engages oncurtain hook 17. Using a cylinder 21 the rod is moved along a linearpath 22 (also shown by means of a broken line) to a position under apressure foot 23 of sewing machine 9. The curtain hook can now be sewnonto a curtain 7.

It is noted here that the return movement of rod 20 can already beginonce the position of curtain hook 17 is fixed by pressure foot 23.

FIG. 4 shows the adjusting means 12 in top view. On the upper side ofrotatable disc 11 is arranged a calibration 24 with which the placing ofadjusting member 18 is related to the stated hook height adjustment. Itis noted that in this figure the position of supply holder 10 differsfrom the situation shown in FIG. 3. In addition to the slot 16 inrotatable disc 11, the stop 15 protruding through this slot 16 is alsoclearly shown. This figure also shows rapid coupling means 25 forreleasable connection of supply holder 10 to a support frame 26 suchthat the holder is situated a short distance above rotatable disc 11.Supply holder 10 is thus connected to the fixed components and does notco-rotate with discs 11, 14.

Although the invention is described with reference to only a fewembodiments, it will be apparent to all that the invention is by nomeans limited to the described and shown embodiments. On the contrary,many more variations are possible for the skilled person within thescope of the invention.

What is claimed is:
 1. Device for feeding curtain hooks, which eachconsists of a strip and a hook part connected thereto, to a sewingmachine which can sew the strip of a supplied curtain hook to a curtain,comprising: a supply holder for the curtain hooks, displacing means fordisplacing one curtain hook at a time in a straight line to a desiredposition for sewing on the strip, and adjusting means for automaticallyadjusting a mutual position of the strip and the hook part of the onecurtain hook, wherein the adjusting means transport the one curtain hookin a circle segment-shaped path from a position close to an underside ofthe supply holder to the straight line in which the displacing meansdisplace the one curtain hook, and during a progression through thecircle segment-shaped path, a desired mutual position of the hook partand the strip is adjusted.
 2. Device as claimed in claim 1, wherein thesupply holder consists of a vertical tube in which the curtain hooks arebuffered stacked on top of one another.
 3. Device as claimed in claim 1,wherein the circle segment-shaped path of the adjusting means ends in orclose to the straight line in which the displacing means displace acurtain hook.
 4. Device as claimed in claim 1, wherein the adjustingmeans comprise: at least one rotatable disc, which disc is adapted tocarry a curtain hook, and a stop co-acting with the disc for engaging onthe hook part of the curtain hook during rotation of the rotatable disc.5. Device as claimed in claim 4, wherein the rotatable disc is providedwith locking means for fixing the position of the strip of a curtainhook carried by the disc.
 6. Device as claimed in claim 4, wherein ahook-placement position of the stop is adjustable.
 7. Device as claimedin claim 6, wherein the hook-placement position of the stop isadjustable with an adjusting member lockable in a plurality ofpositions.
 8. Device as claimed in claim 7, wherein a transmission isarranged between the adjusting member and the stop with a transmissionratio from a displacement of the adjusting member to a displacement ofthe stop for adjusting the hook-placement position which is less than 1.9. Method for feeding curtain hooks, which each consist of a strip and ahook part connected thereto, to a sewing machine which can sew the stripof a supplied curtain hook to a curtain, comprising the successive stepsof: A) feeding a curtain hook from a supply holder along a circlesegment-shaped path, a desired mutual position of the strip and the hookpart being adjusted during the progression through this circlesegment-shaped path, and B) further displacing the curtain hook with thedesired mutual position of the strip and the hook part to a sewingmachine along a linear path connecting onto the circle segment-shapedpath.
 10. Method as claimed in claim 9, wherein the desired mutualposition of the strip and the hook part is determined prior toprogressing through step A by adjusting the means for feeding curtainhooks along the circle segment-shaped path.
 11. Method as claimed inclaim 9, wherein the orientation of the curtain hook after progressingthrough step A is the same as the orientation in which the curtain hookis further displaced according to step B.
 12. In a device for feedingcurtain hooks to a sewing machine for the purpose of sewing a strip of asupplied curtain hook to a curtain, the improvement comprising adjustingmeans, said adjusting means comprising: at least one rotatable disc,said disc adapted to carry a curtain hook; and a stop coacting with thedisc for engaging on the hook part of the curtain hook during rotationof the rotatable disc.